So far we have done essentially zero work on suit design. We have talked briefly about the pros and cons of designing our own vs buying Soviet surplus, but that is about it.
I think this might be an area where we can profitably ally ourselves with the Open Luna Foundation, who have actually done some good work on suit design. Here's a link to a slideshow of theirs which outlines lessons learned from them actually doing simulations where people put on prototype suits and do work in either a desert or arctic environment, actually using the suit for breathing, waste disposal, etc. There are few technical details in the slideshow, but it's safe to assume they do actually have a lot of good technical data.
Since a suit which is good enough for their lunar work is good enough for our lunar work and vice versa, and since we currently have basically zero plans of our own, I propose that we make a ruling to simply use their suits. CSTART folk in the Life Support Workgroup who are interested in suit design can work with the OLF people on their suits, and the rest of our CM life support system can be designed to work with their suits (they may even have done work along designing this sort of system – if they haven't, a benefit for them from this arrangement would be being able to use our system).
In essence, I am proposing that there be one open source suit design that both teams design and build jointly and use for their respective lunar missions. Other teams which we find or who are created in the future could chip in too – basically this would be the open suit that all open space teams work on and use together. It may be worth giving this its own project name, possibly its own website and possibly even its own governing body. Regardless of how we set it up, it could be worked on and funded by both CSTART and OLF. We could jointly finance design competitions (back on /r/tothemoon somebody posted links to a space suit glove design competition?), etc.
This would be a great boon to the open space exploration community. If we had a standardised set of plugs/adaptors/whatever on the suit, people (both open groups and private companies) could design and manufacture e.g. oxygen supply systems or temperature control systems or whatever which are "compatible with OpenSuit x.y plugs/adaptors" and anyone using that version of the OpenSuit could buy any one of these systems and just "plug and play"/p>
If people here agree that this is a good idea we should ask the OLF people how they feel and go from there.